1. Field of the Invention
The present invention also relates to processing of pellet-shaped articles, for example, pharmaceuticals such as caplets and tablets. In particular, the present invention relates to drilling holes, e.g., using a laser system, into coated pharmaceutical tablets or caplets, the drilled holes providing for mechanical time-release of medicine within the articles once ingested into the digestive track, e.g. the stomach or intestines.
The present invention also relates to inspecting the laser drilled holes against a standard and actively accepting or rejecting selected ones of the pellet-shaped articles that are properly drilled.
2. Background of the Invention
Inspection units for pellet-shaped articles are known in the art. The inspection units are typically configured to inspect and remove pellet-shaped articles from a conveyer mechanism that have been improperly processed in a previous processing operation. Previous processing operations may include marking the pellet-shaped articles with indicia, coloring the pellet-shaped articles, laser drilling holes in the pellet-shaped articles, and coating the pellet-shaped articles. These processing operations are typically completed upstream from the inspection unit such that the inspection unit may inspect if these processes have been properly completed.
For example, a variety of known devices have been developed for applying a gel coating to pellet-shaped articles. Typically, the pellet-shaped articles, e.g., tablets, capsules, caplets and pills, are coated by having one side of the pellet-shaped article coated at a time. Often, due to a processing error, one or both sides of the pellet-shaped article are not coated at all; e.g., one side of the pellet-shaped article is coated twice. As a result, the pellet-shaped article has at least one side that is not properly coated with gel. It is important for the manufacturer to carefully inspect the pellet-shaped articles for defects, such as an improperly coated side of the article, before the pellet-shaped article is distributed to the consumer so as to ensure the quality of the product and hence protect the safety of the consumer.
An example of an inspection unit is shown in U.S. Pat. No. 5,085,510 (the '510 patent). The '510 patent discloses an inspection unit for detecting laser drilled holes in tablets. As shown in FIG. 1, individual tablet carriers 6 are provided that transport individual tablets 2 in a vertical position past two sets of cameras 12. The cameras 12 are oriented horizontally and analyze opposing sides of the tablets 2 based on predetermined selection criteria. The cameras 12 signal a separation means 24 to divert preselected tablets 2. One significant limitation of the above unit is that only one tablet can be analyzed by a set of cameras at a time. As a result, more than one set of cameras must be utilized to maximize the inspection rate. Moreover, each tablet carrier 6 is only capable of transporting one tablet, which is inspected on both sides thereof. Thus, the '510 patent suffers in that the feed rate is severely limited because only one row of tablets is fed through the inspection unit.
U.S. Pat. No. 5,894,801 to Ackley, Jr., incorporated herein by reference in its entirety, describes a method and apparatus for conveying a plurality of pellet-shaped articles, such as pharmaceuticals. The conveyer conveys the pharmaceuticals past one or more article modifying devices, such as a laser that forms in the pharmaceuticals drilled or blind bore holes that act as a mechanical time-release mechanism. Lasers are known from U.S. Pat. No. 5,376,771, incorporated herein by reference in its entirety.
Known lasers create the time-release holes with a diameter in the range of about 400-800 micrometers, and a depth of about 450-500 micrometers. Depending on the medicine involved and the speed in which the medicine is to be time-released into the digestive track, the article may be provided with a plurality of holes. Typically, the holes are drilled through a coating of the article, which coating makes the article easier to swallow. The coating is encapsulates the medicine or drug until it is released through the laser hole. The coating typically will not dissolve or will dissolve more slowly than the drug or medicine. The holes are provided to allow the stomach and other fluids to penetrate the interior of the articles and thereby create a sort of pumping action to transport the medicinal portion of the article from the interior thereof into the digestive track, e.g., the stomach or intestines, etc.
The above hole dimensions, even if there are a plurality of holes, may not be suitable to allow a person's digestive fluids to penetrate the article and release the medicine in time for proper release of the medicine. Thus, the medicine may not be released along the appropriate portion of the person's digestive track, or it may not be released at all. This can result in diminished effectiveness of the medicine and dissatisfaction to the patient.
Moreover, systems such as shown in U.S. Pat. Nos. 5,433,146, 5,768,996 and 5,836,243, all to Ackley, Jr. and incorporated herein by reference in their entireties, are not suited for carrying out a coordinated series of drilling operations on a plurality of axially spaced rows of articles, because a typical drilling laser system is designed to be used with systems in which only one row of articles is provided.
Further, current inspection systems may require significant processing time to determine whether the processed articles are acceptable and to then separate acceptable articles from those that are unacceptable. For example, inspection of the drilled holes can slow down productivity and processing of the articles, especially if the inspection unit is to be integrated with other components, such as print stations, article handlers, etc. This is further complicated where the conveyer includes a plurality of axially spaced rows being simultaneously processed. The linear speed of systems with a single row of tablets makes it difficult if not impossible to reject only individual tablets. A single bad tablet or article typically causes several tablets, whether good or bad, to be rejected, thereby lowering the overall batch yield.
Accordingly, a need has developed in the art to provide one or more systems which address the concerns described above.
The present invention provides improvements over known inspection units such as the ones described above.